1. Field of the Invention
This invention relates to a joint device, more particularly to a joint device, wherein a spherical shaft is coupled into a spherical bearing member made of resin, and is concerned with a spherical shaft effectively used in a connecting rod for use in a link device of a wiper system in a motor vehicle for example.
2. Statement of the Related Art
In general, in a wiper system for wiping a window glass of a motor vehicle, a link device is used to convert rotary motion of the wiper motor into rocking motion of a wiper arm. In the link device of this type, spherical bearing members are joint members made of resin and are integrally formed (hereinafter referred to as "outsert molded") at opposite end portions of a rod. There may also be used a connecting rod, in which a spherical shaft as being a counterpart joint member is coupled into this spherical bearing member.
In the connecting rod of this type, a spherical shaft is pressed into and coupled with a spherical bearing portion through an opening formed by cutting open a portion of the spherical bearing portion in a spherical bearing member.
It is desirable to readily press the spherical shaft into the spherical bearing member in the joint device of this type. However, if the spherical bearing member is designed so that spherical shaft can be pressed into it by weak force, the spherical shaft tends to slip out of the spherical bearing portion after being assembled.